Soft magnetic alloy and magnetic component

ABSTRACT

Provided is a soft magnetic alloy comprising a composition formula (Fe (1−(α+β)) X1 α X2 β ) (1−(a+b+c+d+e+f)) M a B b P c Si d C e Zn f . X1 denotes at least one selected from Co and Ni; X2 denotes at least one selected from Cu, Mg, Al, Mn, Ag, Sn, Bi, O, N, S, and rare earth elements; M denotes at least one selected from Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, and W; 0.080≤b≤0.150, 0≤c≤0.060, 0≤d≤0.060, 0≤e≤0.030, 0.0030≤f≤0.080, 0.0030≤a+f≤0.080, b+c≥0.100, α≥0, β≥0, and 0≤α+β≤0.50 are satisfied; and the soft magnetic alloy has Fe-based nanocrystals with a bcc structure.

BACKGROUND OF THE INVENTION

The present invention relates to a soft magnetic alloy and a magneticcomponent.

In recent years, there is a demand for higher efficiency and lower powerconsumption in electronic, information, and communication equipment orthe like. Furthermore, the above demand is further strengthened for therealization of a low-carbon society. Therefore, there is also a demandfor improvement of power supply efficiency and reduction of energy lossin a power supply circuit for the electronic, information, andcommunication equipment or the like. As a result, there is a demand forimprovement of saturation magnetic flux density and reduction of coreloss (magnetic core loss) in a magnetic core included in a magneticcomponent used in the power supply circuit. If the core loss is reduced,the energy loss of the power supply circuit decreases, and highefficiency and energy saving of the electronic, information, andcommunication equipment or the like can be achieved.

As one of the methods for reducing the core loss, it is effective toconstitute the magnetic core with a magnetic material having high softmagnetic properties. For example, in Patent Document 1, a Fe—B-M softmagnetic alloy is disclosed. M denotes at least one element selectedfrom Ti, Zr, Hf, V, Nb, Ta, Mo, and W.

-   -   Patent Document 1: Japanese Patent Laid-Open No. 7-268566

Patent Document 1 describes that the soft magnetic properties and thesaturation magnetic flux density of the soft magnetic alloy can beimproved by performing a heat treatment on an amorphous metal producedby liquid phase cooling to deposit fine crystalline phase. However, itis necessary to reduce coercivity in order to improve the soft magneticproperties of the soft magnetic alloy, but reduction in the coercivityhas not been sufficiently considered in Patent Document 1.

The coercivity is mainly derived from magnetocrystalline anisotropy andmagnetoelastic effect. The coercivity derived from the magnetoelasticeffect appears when stress is applied to a magnetic material having alarge magnetostriction. The coercivity derived from themagnetocrystalline anisotropy can be reduced by isotropically depositingnanometer scale fine Fe-based crystal phase.

However, it is also necessary to reduce the magnetostriction in order tosufficiently reduce the coercivity derived from the magnetoelasticeffect. In addition, in a composition region in which the content ratioof M is relatively small and the content ratio of B and P having a roleof enhancing an amorphous forming ability is relatively large, anamorphous state before the heat treatment is uniform and thus finecrystals after the heat treatment are also easy to become uniform.Therefore, it is advantageous for suppressing the magnetocrystallineanisotropy, and a high saturation magnetic flux density is obtained.However, on the other hand, the magnetostriction tends to increase. As aresult, there is a problem that, during the manufacturing of themagnetic component, the property deterioration due to the residualstress caused by the magnetostriction becomes remarkable.

BRIEF SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstances,and an objective thereof is to provide a soft magnetic alloy capable ofachieving both low coercivity and high saturation magnetic flux densityby reducing both the magnetostriction and the magnetocrystallineanisotropy.

Aspects of the present invention includes:

-   -   [1] A soft magnetic alloy comprising a composition formula

(Fe_((1−(α+β)))X1_(α)X2_(β))_((1−a+b+c+d+e+f)))M_(a)B_(b)P_(c)Si_(d)C_(e)Zn_(f),

-   -   wherein X1 denotes at least one selected from the group        consisting of Co and Ni;    -   X2 denotes at least one selected from the group consisting of        Cu, Mg, Al, Mn, Ag, Sn, Bi, O, N, S, and rare earth elements;    -   M denotes at least one selected from the group consisting of Ti,        V, Cr, Zr, Nb, Mo, Hf, Ta, and W;    -   a, b, c, d, e, f, α and β satisfy the relationships of:

0.080≤b≤0.150,

0≤c≤0.060,

0≤d≤0.060,

0≤e≤0.030,

0.0030≤f≤0.080,

0.0030≤a+f≤0.080,

b+c≥0.100,

a≥0,

β≥0, and

0≤α+β≤0.50; and

-   -   the soft magnetic alloy has Fe-based nanocrystals with a bcc        structure.

[2] The soft magnetic alloy according to [1], satisfying therelationships of:

c≤0.040,

d≤0.030,

0.010≤f≤0.050, and

0.010≤a+f≤0.050.

[3] The soft magnetic alloy according to [1] or [2], wherein anexpansion value of a (110) plane spacing of the Fe-based nanocrystalwith respect to a (110) plane spacing of pure iron is 0.002 angstroms orless.

[4] The soft magnetic alloy according to any one of [1] to [3], whereinan average grain size of the Fe-based nanocrystal is 5 nm or more and 30nm or less.

[5] The soft magnetic alloy according to any one of [1] to [4] having aribbon shape.

[6] The soft magnetic alloy according to any one of [1] to [4] having apowder shape.

[7] A magnetic component comprising the soft magnetic alloy according toany one of [1] to [4].

According to the present invention, it is possible to provide a softmagnetic alloy capable of achieving both low coercivity and highsaturation magnetic flux density.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention is described in detail in thefollowing order.

-   -   1. Soft magnetic alloy    -   2. Manufacturing method for soft magnetic alloy    -   3. Magnetic component

(1. Soft Magnetic Alloy)

The soft magnetic alloy of the present embodiment has Fe-basednanocrystals and amorphous. The Fe-based nanocrystal is a crystal ofwhich the crystal grain size is in the nanometer scale and which has abcc (body-centered cubic lattice) structure. In the soft magnetic alloy,many Fe-based nanocrystals are deposited and dispersed in the amorphous.A soft magnetic alloy in which the Fe-based nanocrystals are dispersedin the amorphous is easy to exhibit high saturation magnetic fluxdensity and low coercivity.

In the present embodiment, the average crystal grain size of theFe-based nanocrystal is preferably 5 nm or more and 30 nm or less. Withthe average crystal grain size in the above range, it is easy to achievelow magnetostriction, high saturation magnetic flux density, and lowcoercivity.

Subsequently, the composition of the soft magnetic alloy of the presentembodiment is described in detail.

The composition of the soft magnetic alloy of the present embodiment isrepresented by a composition formula(Fe_((1−(α+β)))X1_(α)X2_(β))_((1−(a+b+c+d+e+f)))M_(a)B_(b)P_(c)Si_(d)C_(e)Zn_(f).

In the above composition formula, M denotes at least one elementselected from the group consisting of Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, andW.

In addition, “a” represents the content ratio of M. In the presentembodiment, “a” is determined by the relationship with “f” (describedlater) representing the content ratio of Zn.

In the above composition formula, “b” represents the content ratio of B(boron), and “b” satisfies 0.080<b<0.150. The content ratio (b) of B ispreferably 0.130 or less.

In the above composition formula, “c” represents the content ratio of P(phosphorus), and “c” satisfies 0<c<0.060. That is, P is an optionalcomponent. The content ratio (c) of P is preferably 0.005 or more, andmore preferably 0.010 or more. In addition, the content ratio (c) of Pis preferably 0.040 or less.

In the present embodiment, the sum of the content ratios of B and Psatisfies b+c≥0.100.

When “c” is within the above range, the coercivity tends to decrease.When “c” is too small, the above effects tend to be hardly obtained. Onthe other hand, when “c” is too large, the crystal grain size after theheat treatment tends to increase, and thus the coercivity tends toincrease. When b+c is within the above range, homogeneity of amorphousphase during liquid phase quenching becomes high, uniform fine crystalscan be obtained after the heat treatment, and thus the coercivity tendsto decrease.

In the composition region in which the content ratios of B and P arerelatively large and M is contained in a predetermined ratio, astructure is obtained in which the amorphous forming ability duringliquid phase cooling of a raw material alloy is high and finenanocrystals are deposited after the heat treatment of the alloyobtained by cooling. As a result, a soft magnetic alloy with suppressedmagnetocrystalline anisotropy is obtained easily. In addition, highsaturation magnetic flux density is obtained easily in a region in whichthe content ratio of M is relatively small.

However, the soft magnetic alloy having the above composition regiontends to have large positive magnetostriction. As described above, thecoercivity is affected by not only the magnetocrystalline anisotropy butalso the magnetoelastic effect. If the magnetoelastic effect is great,that is, when the magnetostriction is large, the coercivity may not besufficiently reduced.

Thus, in the present embodiment, a predetermined amount of Zn (zinc) iscontained in the soft magnetic alloy. In this way, it is possible toreduce the positive magnetostriction of the soft magnetic alloy whilemaintaining the structure having fine nanocrystals and the highsaturation magnetic flux density. In other words, the soft magneticalloy of the present embodiment exhibits small coercivity and highsaturation magnetic flux density, because both the magnetocrystallineanisotropy and the magnetoelastic effect are reduced.

Specifically, in the above composition formula, “f” represents thecontent ratio of Zn, and “f” satisfies 0.003≤f≤0.080, and “a” and “f”satisfy 0.003≤a+f≤0.080. That is, in the present embodiment, M issubstituted with Zn (zinc). Zn may substitute all of M, or maysubstitute a part of M within the above range.

When “f” is too small, the magnetostriction reduction effect is small.As a result, the coercivity may not be reduced. On the other hand, when“f” is too large, the saturation magnetic flux density tends to decreaseeasily and the magnetostriction tends to increase.

In the present embodiment, “f” is preferably 0.010 or more. On the otherhand, “f” is preferably 0.050 or less. In addition, a+f is preferably0.010 or more. On the other hand, a+f is preferably 0.050 or less.

A mechanism in which the magnetostriction can be reduced by substitutingM with Zn is not clear, but it can be inferred, for example, as follows.

One of the factors for the increase in magnetostriction is the expansionin the lattice spacing of bcc caused by solid-solution of M in theFe-based nanocrystals having a bcc structure. Because Zn has an atomicradius smaller than that of the M element, the expansion of the latticespacing of bcc can be suppressed when Zn, instead of M, is solid-solutedin the Fe-based nanocrystals. As a result, the positive magnetostrictionof the Fe-based nanocrystals is considered to decrease. In addition, thelattice spacing tends to expand when Zn is added excessively, and as aresult, the magnetostriction reduction effect is considered todecreases.

In addition to the above, because negative magnetostriction of the bccstructure is considered to increase when Zn is solid-soluted in theFe-based nanocrystals, the positive magnetostriction of the Fe-basednanocrystals is considered to decrease thereby.

Moreover, similar to M, Zn also has the effect of refinement of theFe-based nanocrystals, and thus it is possible to obtain a soft magneticalloy of which the magnetostriction is reduced while the structurehaving fine nanocrystals is maintained.

In addition, it is preferable to suppress the solid-solution of M in bccregardless of the presence or absence of the solid-solution of Zn inbcc. As described above, the lattice spacing of bcc expands when M issolid-soluted in bcc, and thus the expansion in the lattice spacing ofbcc is preferably equal to or less than a predetermined value.

In the present embodiment, a (110) plane spacing of bcc is employed asthe lattice spacing of bcc. Because pure iron does not contain M, M isnot solid-soluted in bcc of pure iron. That is, the expansion in theplane spacing caused by the solid-solution of M in bcc does not occur.Accordingly, it means that the closer the (110) plane spacing of thesoft magnetic alloy is to the (110) plane spacing of the pure iron, thelower the solid-solution ratio of M in bcc is.

In the present embodiment, a value obtained by subtracting the (110)plane spacing of pure iron from the (110) plane spacing of the softmagnetic alloy is defined as an expansion value of the (110) planespacing. The expansion value of the (110) plane spacing is preferably0.002 angstroms or less.

With the expansion value of the (110) plane spacing in the above range,the magnetostriction of the soft magnetic alloy can be reduced.

The (110) plane spacing of the soft magnetic alloy and the (110) planespacing of pure iron can be calculated by XRD (X-Ray Diffraction)measurement. That is, the (110) plane spacing can be calculated from theangle at which a diffraction peak of the (110) plane is observed and thewavelength of X-ray. Then, the expansion value of the (110) planespacing may be calculated based on the calculated spacing.

Note that, in order to reduce the influence of the inherent error of theXRD measurement device, the (110) plane spacing of the soft magneticalloy and the (110) plane spacing of pure iron are preferably measuredwith the same device and under the same measurement conditions.

In the above composition formula, “d” represents the content ratio of Si(silicon), and “d” satisfies 0<d<0.060. That is, Si is an optionalcomponent. The content ratio (d) of Si is preferably 0.001 or more, andmore preferably 0.005 or more. In addition, the content ratio (d) of Siis preferably 0.030 or less.

When “d” is within the above range, there is a tendency that theresistivity of the soft magnetic alloy is particularly easy to beimproved, and the coercivity is reduced easily. On the other hand, when“d” is too large, the coercivity of the soft magnetic alloy tends toincrease.

In the above composition formula, “e” represents the content ratio of C(carbon), and “e” satisfies 0<e<0.030. That is, C is an optionalcomponent. The content ratio (e) of C is preferably 0.001 or more. Inaddition, the content ratio (e) of C is preferably 0.015 or less.

When “e” is within the above range, there is a tendency that thecoercivity of the soft magnetic alloy is particularly easy to bereduced. When “e” is too large, the crystal grain size tends to increaseand the coercivity tends to increase.

In the above composition formula, 1−(a+b+c+d+e+f) represents the totalcontent ratio of Fe (iron), X1 and X2. The total content ratio of Fe, X1and X2 is not particularly limited as long as “a”, “b”, “c”, “d”, “e”and “f” are within the above ranges. In the present embodiment, thetotal content ratio (1−(a+b+c+d+e+f)) is preferably 0.73 or more and0.95 or less. With the total content ratio set to 0.73 or more, highsaturation magnetic flux density is obtained easily. In addition, withthe total content ratio set to 0.95 or less, crystal phase configured bycrystals having a grain size larger than 30 nm is hardly generated. As aresult, a soft magnetic alloy in which the Fe-based nanocrystals aredeposited by heat treatment tends to be obtained easily.

X1 denotes at least one element selected from the group consisting of Coand Ni. In the above composition formula, “a” represents the contentratio of X1, and “α” is 0 or more in the present embodiment. That is, X1is an optional component.

In addition, when the total number of atoms of the composition is set to100 at %, the number of atoms of X1 is preferably 40 at % or less. Thatis, it is preferable to satisfy 0≤a {1−(a+b+c+d+e+f)}≤0.40.

X2 denotes at least one element selected from the group consisting ofCu, Mg, Al, Mn, Ag, Sn, Bi, O, N, S, and rare earth elements. In theabove composition formula, “0” represents the content ratio of X2, and“β” is 0 or more in the present embodiment. That is, X2 is an optionalcomponent.

In addition, when the total number of atoms of the composition is set to100 at %, the number of atoms of X2 is preferably 3.0 at % or less. Thatis, it is preferable to satisfy 0≤β{1−(a+b+c+d+e+f)}≤0.030.

Furthermore, the range (substitution ratio) in which X1 and/or X2substitutes for Fe is set equal to or less than half of the total numberof Fe atoms in terms of the number of atoms. That is, 0≤α+β≤0.50 issatisfied. When α+β is too large, it tends to be difficult to obtain asoft magnetic alloy in which the Fe-based nanocrystals are deposited byheat treatment.

Note that, the soft magnetic alloy of the present embodiment may includeelements other than the above elements as inevitable impurities. Forexample, the elements other than the above elements may be included in atotal of 0.1% by mass or less with respect to 100% by mass of the softmagnetic alloy.

(2. Manufacturing Method of Soft Magnetic Alloy)

Subsequently, a method for manufacturing the soft magnetic alloy isdescribed. The soft magnetic alloy of the present embodiment ismanufactured by, for example, depositing Fe-based nanocrystals in anamorphous alloy having the above composition.

As the method for obtaining the amorphous alloy, for example, a methodof quenching a molten metal to obtain an amorphous alloy is exemplified.In the present embodiment, a ribbon or flake of the amorphous alloy maybe obtained by a single roll method, or powder of the amorphous alloymay be obtained by an atomization method. Hereinafter, a method ofobtaining the amorphous alloy by the single roll method and a method ofobtaining the amorphous alloy by a gas atomization method as an exampleof the atomization method are described.

In the single roll method, first, a raw material (pure metal or thelike) of each metal element contained in the soft magnetic alloy isprepared and is weighed so as to obtain a composition of the finallyobtained soft magnetic alloy, and the raw material is melted to obtainmolten metal. Note that, the method for melting the raw material of themetal elements is not particularly limited; for example, a method ofmelting the material by high-frequency heating in a predeterminedatmosphere is exemplified. The temperature of the molten metal may bedetermined in consideration of the melting point of each metal elementand may be, for example, 1200-1500° C.

Next, for example, inside a chamber filled with an inert gas, the moltenmetal is injected and supplied from a nozzle to a cooled rotary roll,and thereby a ribbon-shaped or flaky amorphous alloy is manufacturedtoward the rotating direction of the rotary roll. Examples of thematerial of the rotary roll include copper. The temperature of therotary roll, the rotating speed of the rotary roll, the atmosphereinside the chamber, and the like may be determined corresponding to theconditions under which the Fe-based nanocrystals are easily deposited inthe amorphous during the heat treatment described later.

In the gas atomization method, similar to the single roll method, first,molten metal is obtained in which the raw material of the soft magneticalloy is melted. The temperature of the molten metal may be determinedin consideration of the melting point of each metal element as in thecase of the single roll method, and may be, for example, 1200-1500° C.

The obtained molten metal is supplied into the chamber as a linearcontinuous fluid through a nozzle provided at the bottom of thecrucible, and a high-pressure gas is sprayed onto the supplied moltenmetal to make the molten metal into droplets, and the droplets arequenched to obtain a powder-shaped amorphous alloy. The gas injectiontemperature, the pressure in the chamber, and the like may be determinedcorresponding to the conditions under which the Fe-based nanocrystalsare easily deposited in the amorphous during the heat treatmentdescribed later. In addition, the particle size can be adjusted bysieving classification, airflow classification, or the like.

The ribbon and powder obtained by the above methods are configured by anamorphous alloy. The amorphous alloy may be an amorphous alloy in whichfine crystals are dispersed in an amorphous, or may be an alloy notcontaining crystals.

Next, the obtained ribbon and powder are subjected to a heat treatment(first heat treatment). By performing the first heat treatment,diffusion of the elements constituting the soft magnetic alloy can bepromoted, a thermodynamic equilibrium state can be achieved in a shorttime, and strain or stress existing in the soft magnetic alloy can beremoved. As a result, it becomes easy to obtain a soft magnetic alloy inwhich the Fe-based nanocrystals are deposited.

In the present embodiment, the condition of the first heat treatment isnot particularly limited as long as the Fe-based nanocrystals are easilydeposited under this condition. In the case of ribbon, for example, theheat treatment temperature can be set to 400-700° C., and the holdingtime can be set to 0.5-10 hours.

In the present embodiment, it is preferable to further perform a heattreatment (second heat treatment) after the first heat treatment. Byperforming the second heat treatment, M solid-soluted in the Fe-basednanocrystals can be released out of the crystals. In the case of acomposition containing a relatively large amount of Zn, excessivelysolid-soluted Zn can be released out of the crystals and the amount ofsolid-solution Zn in the crystals can be optimized. As a result, the(110) plane spacing of the Fe-based nanocrystal decreases and gets closeto the (110) plane spacing of pure iron, and thus the magnetostrictioncan be reduced.

The heat treatment temperature of the second heat treatment ispreferably lower than the heat treatment temperature of the first heattreatment, and more preferably lower by 50° C. or more. In addition, theholding time of the second heat treatment is preferably three hours orlonger and ten hours or shorter.

After the above heat treatment, the soft magnetic alloy of the presentembodiment having a ribbon shape or the soft magnetic alloy of thepresent embodiment having a powder shape is obtained.

In addition, there is no particular limitation on the calculation methodof the average grain size of the Fe-based nanocrystals contained in thesoft magnetic alloy obtained by the heat treatment. For example, thecalculation can be made by a transmission electron microscopeobservation. In addition, there is no particular limitation on a methodfor confirming that the crystal structure is a bcc (body-centered cubiclattice) structure. For example, the confirmation can be made usingX-ray diffraction measurement.

(3. Magnetic Component)

The magnetic component of the present embodiment is not particularlylimited as long as this magnetic component includes the above softmagnetic alloy as a magnetic material. For example, the magneticcomponent may have a magnetic core configured by the above soft magneticalloy.

Examples of the method for obtaining a magnetic core from theribbon-shaped soft magnetic alloy include a method of winding theribbon-shaped soft magnetic alloy or a method of laminating theribbon-shaped soft magnetic alloy. When the ribbon-shaped soft magneticalloy is laminated via an insulator during the lamination, a magneticcore with further improved properties can be obtained.

Examples of the method for obtaining a magnetic core from thepowder-shaped soft magnetic alloy include a method in which thepowder-shaped soft magnetic alloy is appropriately mixed with a binderand then molded using a press mold. In addition, by applying anoxidation treatment, an insulating coating or the like on the powdersurface before the mixture with the binder, the magnetic core has animproved resistivity and is adapted to higher frequency regions.

The magnetic component of the present embodiment is suitable for a powerinductor used in a power supply circuit. In addition, applications ofthe magnetic core include, in addition to the inductor, a transformer, amotor, and the like.

The present embodiment of the present invention has been describedabove, but the present invention is not limited to the above embodimentand may be modified in various aspects within the scope of the presentinvention.

EXAMPLES

Hereinafter, the present invention is described in more detail withreference to examples, but the present invention is not limited to theseexamples.

Examples 1-21 and Comparative Examples 1-10

First, raw metal of the soft magnetic alloy was prepared. The preparedraw metal was weighed so as to satisfy the composition shown in Table 1and was melted by high-frequency heating to prepare a mother alloy.

Then, the prepared mother alloy was heated and melted to obtain moltenmetal having a melting temperature of 1250° C. The molten metal wassprayed on a rotary roll by a single roll method to form a ribbon. Notethat, the material of the rotary roll was Cu. In addition, the standardrotating speed of the rotary roll was 25 m/sec. By adjusting the rollrotating speed, the thickness of the obtained ribbon was set to 20 μm-30μm, the width of the ribbon was set to 4 mm-5 mm, and the length of theribbon was set to tens of meters.

As a result of performing X-ray diffraction measurement on each of theobtained ribbons, in all the examples, the ribbon had an amorphous or ananohetero-structure in which initial fine crystals exist in theamorphous.

Then, the ribbons of Examples 1-21 and Comparative Examples 1-10 weresubjected to heat treatment at a heat treatment temperature of 550° C.and for a holding time of one hour. As a result of the X-ray diffractionmeasurement and the transmission electron microscope observationperformed on the ribbon after the heat treatment, in all the examples,it was confirmed that the ribbon after the heat treatment had Fe-basednanocrystals of which the crystal structure was bcc and the averagecrystal grain size of the Fe-based nanocrystals was 5-30 nm. Inaddition, it was confirmed by ICP analysis that there was no change inthe alloy composition before and after the heat treatment.

The magnetostriction, saturation magnetic flux density, and coercivitywere measured for each ribbon after the heat treatment. Themagnetostriction was measured by a strain gauge method. The saturationmagnetic flux density (Bs) was measured using a vibrating samplemagnetometer (VSM) at a magnetic field of 1000 kA/m. The coercivity (Hc)was measured using a direct current BH tracer at a magnetic field of 5kA/m.

Regarding the magnetostriction, a sample in which the absolute value ofmagnetostriction is 2.50 ppm or less was judged to be good. A sample inwhich the absolute value of magnetostriction is 1.50 ppm or less is morepreferable. Regarding the saturation magnetic flux density, a sample inwhich the saturation magnetic flux density was 1.40 T or more was judgedto be good. A sample in which the saturation magnetic flux density is1.60 T or more was more preferable. Regarding the coercivity, a samplein which the coercivity is 2.0 A/m or less was judged to be good. Asample in which the coercivity is 1.5 A/m or less is more preferable.The results are shown in Table 1.

The value of the coercivity measured as described above includes both acomponent derived from the magnetocrystalline anisotropy and a componentderived from the magnetoelastic effect caused by the magnetostriction.The component derived from the magnetoelastic effect is the product ofthe magnetostriction and the stress and thus cannot be detected ascoercivity when the internal stress is not applied to the sample.Accordingly, it is necessary to confirm that both the coercivity and themagnetostriction show a low value and the saturation magnetic fluxdensity shows a high value, in order to determine whether the effect ofthe present invention exists.

In view of the situation described above, in Table 1 and Tables 2-4described later, as shown below, scores corresponding to the measuredproperty values were allocated to each sample, and the superiority ofthe samples was comprehensively evaluated according to the numericalvalue of the product of the scores. The results are shown in a column ofcomprehensive evaluation.

With respect to each sample, zero point was allocated when themagnetostriction is greater than 2.50 ppm, one point was allocated whenthe magnetostriction is greater than 1.50 ppm and equal to or lower than2.50 ppm, and two points were allocated when the magnetostriction is1.50 ppm or less. With respect to each sample, zero point was allocatedwhen the saturation magnetic flux density is less than 1.40 T, one pointwas allocated when the saturation magnetic flux density is 1.40 T ormore and less than 1.60 T, and two points were allocated when thesaturation magnetic flux density is 1.60 T or more. With respect to eachsample, zero point was allocated when the coercivity is greater than 2.0A/m, one point was allocated when the coercivity is greater than 1.5 A/mand equal to or lower than 2.0 A/m, and two points were allocated whenthe coercivity is 1.5 A/m or less. Then, the product of the allocatednumerical values was calculated and a sample in which the numericalvalue of the product was equal to or greater than 1 was judged to begood.

TABLE 1 Soft magnetic alloy PropertyFe_((1−a−b−c−d−e−f))M_(a)B_(b)P_(c)Si_(d)C_(e)Zn_(f)□α Saturation = β =0 Magneto- magnetic flux Coer- Fe striction density civity Compre- 1 − a− b − c − B P Si C M Zn λ Bs Hc hensive d − e − f b c d e Element a fa + f b + c (×10⁻⁶) (T) (A/m) evaluation Example 1 0.830 0.120 0.0000.000 0.000 — 0.000 0.050 0.050 0.120 1.13 1.63 1.7 4 Example 2 0.8500.120 0.000 0.000 0.000 — 0.000 0.030 0.030 0.120 0.63 1.72 1.5 8Example 3 0.860 0.130 0.000 0.000 0.000 — 0.000 0.010 0.010 0.130 0.971.74 1.8 4 Example 4 0.830 0.120 0.000 0.000 0.000 Nb 0.020 0.030 0.0500.120 1.40 1.65 1.0 8 Example 5 0.850 0.120 0.000 0.000 0.000 Nb 0.0100.020 0.030 0.120 0.85 1.70 1.2 8 Example 6 0.847 0.150 0.000 0.0000.000 — 0.000 0.003 0.003 0.150 2.39 1.63 1.8 2 Example 7 0.820 0.1000.000 0.000 0.000 — 0.000 0.080 0.080 0.100 1.72 1.48 1.7 1 Example 80.820 0.100 0.000 0.000 0.000 Nb 0.040 0.040 0.080 0.100 1.59 1.43 1.3 2Example 9 0.840 0.090 0.040 0.000 0.000 — 0.000 0.030 0.030 0.130 0.891.65 1.3 8 Example 10 0.830 0.080 0.060 0.000 0.000 — 0.000 0.030 0.0300.140 2.33 1.55 1.1 2 Example 11 0.840 0.100 0.000 0.030 0.000 — 0.0000.030 0.030 0.100 1.46 1.70 1.3 8 Example 12 0.810 0.100 0.000 0.0600.000 — 0.000 0.030 0.030 0.100 2.43 1.57 1.1 2 Example 13 0.840 0.1000.000 0.000 0.030 — 0.000 0.030 0.030 0.100 1.05 1.71 1.3 8 Example 140.830 0.120 0.000 0.000 0.000 Ti 0.020 0.030 0.050 0.120 1.41 1.64 1.5 8Example 15 0.830 0.120 0.000 0.000 0.000 V 0.020 0.030 0.050 0.120 1.471.62 1.3 8 Example 16 0.830 0.120 0.000 0.000 0.000 Cr 0.020 0.030 0.0500.120 1.99 1.62 1.5 4 Example 17 0.830 0.120 0.000 0.000 0.000 Zr 0.0200.030 0.050 0.120 1.39 1.60 0.8 8 Example 18 0.830 0.120 0.000 0.0000.000 Mo 0.020 0.030 0.050 0.120 1.80 1.60 1.2 4 Example 19 0.830 0.1200.000 0.000 0.000 Hf 0.020 0.030 0.050 0.120 1.74 1.61 0.8 4 Example 200.830 0.120 0.000 0.000 0.000 Ta 0.020 0.030 0.050 0.120 1.68 1.60 1.0 4Example 21 0.830 0.120 0.000 0.000 0.000 W 0.020 0.030 0.050 0.120 1.551.63 1.3 4 Comparative 0.820 0.100 0.000 0.000 0.000 Nb 0.080 0.0000.080 0.100 2.78 1.38 0.7 0 Example 1 Comparative 0.830 0.120 0.0000.000 0.000 Nb 0.050 0.000 0.050 0.120 8.01 1.55 1.4 0 Example 2Comparative 0.850 0.120 0.000 0.000 0.000 Nb 0.030 0.000 0.030 0.1204.61 1.66 1.7 0 Example 3 Comparative 0.860 0.130 0.000 0.000 0.000 Nb0.010 0.000 0.010 0.130 2.65 1.71 1.9 0 Example 4 Comparative 0.7900.120 0.000 0.000 0.000 — 0.000 0.090 0.090 0.120 3.88 1.32 2.4 0Example 5 Comparative 0.848 0.150 0.000 0.000 0.000 — 0.000 0.002 0.0020.150 2.82 1.65 4.5 0 Example 6 Comparative 0.790 0.120 0.000 0.0000.000 Nb 0.050 0.040 0.090 0.120 5.32 1.45 1.4 0 Example 7 Comparative0.880 0.090 0.000 0.000 0.000 — 0.000 0.030 0.030 0.090 0.60 1.68 135 0Example 8 Comparative 0.810 0.160 0.000 0.000 0.000 — 0.000 0.030 0.0300.160 4.03 1.61 78 0 Example 9 Comparative 0.870 0.070 0.030 0.000 0.000— 0.000 0.030 0.030 0.100 0.70 1.64 23 0 Example 10

From Table 1, it was confirmed that the numerical value of the productis equal to or greater than 1 when the content ratios of boron and zinc,the total content ratio of M and zinc, and the total content ratio ofboron and phosphorus are within the above-described range. Inparticular, it was confirmed that the numerical value of the product isequal to or greater than 4 and particularly good properties are obtainedwhen the content ratio of zinc, the total content ratio of M and zinc,the content ratio of phosphorus, and the content ratio of silicon arewithin the preferable range described above.

On the contrary, it was confirmed that when zinc is not contained(Comparative Examples 1-4), the magnetostriction is large and the aboveeffect is not obtained even if the other content ratios are within theabove ranges. In addition, it was confirmed that when the content ratioof zinc is too large (Comparative Example 5) and too small (ComparativeExample 6), the magnetostriction is also large and the above effect isnot obtained either.

In addition, it was confirmed that when the total content ratio of M andzinc is too large (Comparative Example 7), the magnetostriction is largeand the above effect is not obtained.

Furthermore, it was confirmed that when the sum of the content ratios ofboron and phosphorus (b+c) is too small (Comparative Example 8) and whenthe content ratio of boron is too small even if b+c is within the aboverange (Comparative Example 10), the coarse grain growth of initial finecrystals occurs during the heat treatment and thus the coercivityincreases. In addition, it was confirmed that when the content ratio ofboron is too large (Comparative Example 9), the magnetostrictionincreases and the coercivity increases due to the generation of aniron-boron compound such as Fe₃B or the like.

Examples 22-34

Except that the “X1” and “X2” elements in the composition formula andthe content ratios in the sample of Example 4 were set to the elementsand the content ratios shown in Table 2, the soft magnetic alloy wasproduced in the same manner as in Example 4, and the same evaluation asin Example 4 was performed. The results are shown in Table 2.

TABLE 2 Property Soft magnetic alloy Saturation(Fe_((1−α−β))X1_(α)X2_(β))_((1−a−b−c−d−e−f))M_(a)B_(b)P_(c)Si_(d)C_(e)Zn_(f)Magneto- magnetic flux Coer- X1 X2 striction density civity Compre- α (1− a − b − c − β (1 − α − b − c − λ Bs Hc hensive element d − e − f)element d − e − f) (×10⁻⁶) (T) (A/m) evaluation Example 22 Co 0.1 — —1.42 1.69 1.7 4 Example 23 Co 0.4 — — 1.48 1.74 1.9 4 Example 24 Ni 0.1— — 1.69 1.66 1.5 4 Example 25 Ni 0.4 — — 2.28 1.56 1.5 4 Example 26 — —Cu 0.008 1.37 1.72 1.7 4 Example 27 — — Mg 0.03 1.33 1.66 1.7 4 Example28 — — Al 0.03 1.48 1.65 1.8 4 Example 29 — — Mn 0.03 1.49 1.58 1.5 4Example 30 — — Ag 0.012 1.55 1.67 1.4 4 Example 31 — — Sn 0.03 1.22 1.621.5 8 Example 32 — — Bi 0.03 1.40 1.61 1.6 4 Example 33 — — Y 0.03 1.431.59 1.4 4 Example 34 — — La 0.03 1.44 1.52 1.3 4

From Table 2, it was confirmed that good properties are obtained evenwhen the element and the content ratios of the X1 element and the X2element are changed.

Examples 35-38

Except that the heat treatment (second heat treatment) was performedunder the conditions shown in Table 3 after the heat treatment (firstheat treatment) performed at 550° C. for one hour for the sample ofExample 8, the soft magnetic alloy was produced in the same manner as inExample 8. For the obtained soft magnetic alloy, in addition to the sameevaluation as in Example 8, the (110) plane spacing was calculated.

The (110) plane spacing was calculated from 20 of the strongest peakbelonging to the (110) plane among the diffraction peaks obtained by theXRD measurement and the wavelength of the measurement X-ray. Inaddition, for the sample of pure iron, the (110) plane spacing wascalculated under the condition under which the above XRD measurement wasperformed using the same device as that used for the above XRDmeasurement. By subtracting the obtained spacing value of the (110)plane of pure iron from the obtained spacing value of the (110) plane ofthe soft magnetic alloy, the expansion values of the (110) plane spacingin the samples of Example 8 and Examples 35-38 were obtained. Theresults are shown in Table 3.

TABLE 3 Fe_(0.820)Nb_(0.040)B_(0.100)Zn_(0.040) α = β = 0 c = d = e = 0Fe-based nanocrystal Property Heat treatment condition ExpansionSaturation Second heat Average of 110 Magneto- magnetic flux Coer- Firstheat treatment treatment grain plane striction density civity Compre-Temperature Time Temperature Time size spacing λ Bs Hc hensive (° C.)(h) (° C.) (h) (nm) (Å) (×10⁻⁶) (T) (A/m) evaluation Example 8 550 1 — 026 0.0029 1.59 1.43 1.3 2 Example 35 550 0.25 450 1 25 0.0026 1.54 1.661.7 2 Example 36 550 0.25 450 3 24 0.0020 1.18 1.64 1.8 4 Example 37 5500.25 450 5 26 0.0016 0.98 1.66 1.7 4 Example 38 550 0.25 450 10 270.0005 0.79 1.67 1.8 4

From Table 3, it was confirmed that the expansion value of the (110)plane spacing decreases due to the heat treatment at a lower temperaturethan that in the first heat treatment and the magnetostriction alsodecreases accordingly. Furthermore, it was confirmed that the expansionvalue of the (110) plane spacing decreases when the holding time of thesecond heat treatment is prolonged and the magnetostriction alsodecreases accordingly.

Examples 39-43

Except that the heat treatment conditions in the sample of Example 4were changed to those shown in Table 4, the soft magnetic alloy wasproduced in the same manner as in Example 4, and the same evaluation asin Example 4 was performed. The results are shown in Table 4.

TABLE 4 Property Fe_(0.830)Nb_(0.020)B_(0.120)Zn_(0.030) α = β = 0 c = d= e = 0 Saturation Fe-based Magneto- magnetic flux Coer- Heat treatmentcondition nanocrystal striction density civity Compre- First heattreatment Average grain size λ Bs Hc hensive Temperature (° C.) Time (h)(nm) (×10⁻⁶) (T) (A/m) evaluation Example 39 400 1 3 2.37 1.41 0.8 2Example 40 450 1 5 1.49 1.60 1.0 8 Example 41 500 1 21 1.47 1.62 1.1 8Example 4 550 1 27 1.40 1.65 1.0 8 Example 42 600 1 30 1.42 1.69 1.5 8Example 43 650 1 32 1.39 1.69 1.9 4

From Table 4, it was confirmed that good properties are obtained whenthe average grain size of the Fe-based nanocrystals is within the aboverange.

What is claimed is:
 1. A soft magnetic alloy comprising a compositionformula(Fe_((1−(α+β)))X1_(α)X2_(β))_((1−(a++b+c+d+e+f)))M_(α)B_(b)P_(c)Si_(d)C_(e)Zn_(f),wherein X1 denotes at least one selected from the group consisting of Coand Ni; X2 denotes at least one selected from the group consisting ofCu, Mg, Al, Mn, Ag, Sn, Bi, O, N, S, and rare earth elements; M denotesat least one selected from the group consisting of Ti, V, Cr, Zr, Nb,Mo, Hf, Ta, and W; a, b, c, d, e, f, α and β satisfy the relationshipsof:0.080≤b≤0.150,0≤c≤0.060,0≤d≤0.060,0≤e≤0.030,0.0030≤f≤0.080,0.0030≤α+β≤0.080,b+c≥0.100,α≥0,β≥0, and0≤α+β≤0.50; and the soft magnetic alloy has Fe-based nanocrystals with abcc structure.
 2. The soft magnetic alloy according to claim 1,satisfying the relationships of:c≤0.040,d≤0.030,0.010≤f≤0.050, and0.010≤a+f≤0.050.
 3. The soft magnetic alloy according to claim 1,wherein an expansion value of a (110) plane spacing of the Fe-basednanocrystal with respect to a (110) plane spacing of pure iron is 0.002angstroms or less.
 4. The soft magnetic alloy according to claim 2,wherein an expansion value of a (110) plane spacing of the Fe-basednanocrystal with respect to a (110) plane spacing of pure iron is 0.002angstroms or less.
 5. The soft magnetic alloy according to claim 1,wherein an average grain size of the Fe-based nanocrystals is 5 nm ormore and 30 nm or less.
 6. The soft magnetic alloy according to claim 1having a ribbon shape.
 7. The soft magnetic alloy according to claim 1having a powder shape.
 8. A magnetic component comprising the softmagnetic alloy according to claim 1.